Enigma wasn't cracked because of weaknesses in the algorithm(although those do exist), it was broken because of the German's sloppy cryptography practices and the fact that the allies found out what process they were using to determine their keys.

If a cop is wearing body armor, it doesn't mean that he can walk out into a torrent of incoming bullets. Chances are that one of those bullets will find a weakness in his armor, or simply strike him in a place where he's not protected. Similar principle here.

Actualy, if the Poles hadn't been REALLY proactive about truing to break the German Enigma we (the Allies) would have been really fucked. The French had access to Enigma plans but felt that it was impopssible to crack Enigma so they handed all their data to the Poleish intelligence service (Burio Szyfrow)and siad good luck.. Marian Rejewski of the Burio developed an attack on Enigma (absolutely brilliant!!) that actually suceeded in cracking the cipher. The Poles were decrypting German messages on a daily basis until 1938, when the Germans increased the number of scramblers to 5 so that any 3 were available for encryption and also added new plugboards. When Poland was attacked by the Germans the Poles called in the British and gave them spare Enigma replicas they had built, blueprints, and cracking strategies. They were sent to England in diplomatic pouches via Paris. smuggled across the Channel by a French playwrite and his actress wife, so as not to be detected by Geman spies at the Channel ports. Laugh all you want to, but the Poles made it possible to win World War II.

I you would like to use an Enigma machine yourself, just go to this website:
http://users.telenet.be/d.rijmenants/index.htm [telenet.be]
There's an awardwinning Enigma simulation. This program is an exact simulation of the 3-rotor Wehrmacht and the famous 4-rotor Kriegmarine M4 model of the German Enigma cipher machine, used during World War II from 1939 until 1945. You can select between the two models, actually choose different rotors or 'Walzen', preset the rotor wiring positions or 'Ringstellung' and switch letters by using plugs or 'Stecker'. The internal wiring of all rotors is identical to those used by the Wehrmacht, Luftwaffe and Kriegsmarine. Fully compatible with the real Enigma-machine, and you can decode original messages and make your own encoded text!

Although Colossus was classified, a lot of the people who worked on it went on to become the initial wave of computer builders in UK universities after the war. It's also reputed that at least one Colossus survived at Cheltenham into the 1970s, presumably working on multi-wheel stream ciphers.

Who says breaking Enigma doesn't take much time???? 4 out of 8 possible naval rotors, 26 positions, each have also 26 internal ringsetting, two different reflectors, you also need the startposition and the plugs, up to 10 pairs of 26 (only the plugboards gives us already 7,905,853,580,625 combinations). Even today, going through all possible keys is a mission impossible. That's why Stefan used the Hill Climbing Algorithm to break those messages. Pure Brute force would take far to much time. More on the Enigma key settings on NSA's http://www.nsa.gov/publications/publi00004.cfm [nsa.gov]. For more technical details on Enigma, read this one: http://users.telenet.be/d.rijmenants/en/enigmatech .htm [telenet.be]

"If I take a letter, lock it in a safe, hide the safe somewhere in New York, then tell you to read the letter, that's not security. Thats obscurity. On the other hand, if I take a letter and lock it in a safe, and give you the safe along with the design specifications of the safe and a hundred identical safes with their combinations so that you and the worlds best safecrackers can study the locking mechanism - and you still can't open the safe and read the letter - thats security." Applied Cryptography, Bruce Schneier.

A really good crypto system wouldn't need to be embedded in a stream of gibberish to interfere with traffic analysis, as it would be impervious to traffic analysis anyway.

There were several different systems, used by the Allies. For high level traffic, the US used the very secure SIGABA (never reported to be broken, back then). SIGABA was also a rotor machine, but with three different banks of rotors, each performing their special task. In the field, the US Amry used mostly the M-209 Convertor. This was the US version of the Hagelin C-38. It was a so called pin-and-lug machine. You can try out the M-209 on this website: http://users.telenet.be/d.rijmenants/en/m209sim.ht m [telenet.be]

Doesn't the DMCA make it illegal to make tools for breaking encryption or even to discuss how encryption may be broken?

No. You're letting them control you because they always use the acronym.

It is the Digital Millennium Copyright Act. It is first, foremost, and only a copyright act.

The Enigma messages aren't copyrighted in any real sense (copyrights that belonged to the Nazi Party went to interesting places - at one point they were public-domained by an Allied government as "spoils of war"), and moreover the encryption doesn't enforce copy protection. The messages were secured from reading for confidentiality, not from distributing for licensing content.